Measuring the effects of reduced winter snowpack on ground dwelling insect populations in the northeastern U.S

Recent models for the northeastern U.S. predict climate change induced reductions in protective snow cover. Decreases in the thermal buffering of the forest floor resulting from these reductions may lead to earlier and more severe soil freezing. We evaluated the response of ground dwelling insect populations to decreased snowpack because they are highly susceptible to changes in temperature and provide critical ecosystem services. Treatments included four understory vegetation removal and snow removal, understory vegetation removal, and undisturbed control plots at the Hubbard Brook Experimental Forest, New Hampshire. Treatments were repeated for three consecutive winters. We measured the effect of snow removal on soil temperature at five depths within each plot. Insect response to vegetation manipulation was examined relative to the impacts of snowpack manipulation to compare the severity of the effects of these two disturbances. Our data suggests that for the northeastern U.S., the presence of understory vegetation has a greater impact than the presence of a snowpack on ground dwelling insect populations; however, this was not the case for all insect families. We will discuss differences among treatments, intra- and inter-annual variation, and the implications of changes in the composition of ground dwelling insect populations on both the green and brown food webs.